External Drives not recognised

Discussion in 'Computer Support' started by andy, Nov 19, 2009.

  1. andy

    andy Guest

    Could someone throw some light on this one - it's doing my head in ...
    Laptop running vista home premium and ext hd worked until recently
    but now can't be seen by computer when connected to any usb port
    - no drive letter shows in * computer * but drive shows in device
    manager as working properly . There is also usb icon shown in task bar
    I bought a new portable usb HD drive today and have the same problem
    with that.
    Strange thing is both work on other pc which is running windoze xp
    with no problem ......... also have no problem with usb memory sticks
    on both computers . Why is it just the portable drives ?
    Any help most appreciated Cheers
     
    andy, Nov 19, 2009
    #1
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  2. andy

    Rick Merrill Guest

    andy wrote:
    > Could someone throw some light on this one - it's doing my head in ...
    > Laptop running vista home premium and ext hd worked until recently
    > but now can't be seen by computer when connected to any usb port
    > - no drive letter shows in * computer * but drive shows in device
    > manager as working properly . There is also usb icon shown in task bar
    > I bought a new portable usb HD drive today and have the same problem
    > with that.
    > Strange thing is both work on other pc which is running windoze xp
    > with no problem ......... also have no problem with usb memory sticks
    > on both computers . Why is it just the portable drives ?
    > Any help most appreciated Cheers


    You should have only one (1) "primary" partition on any drive, AFIK.

    Try plugging in the USB2 drives AFTER the system has powered up and is
    ready.
     
    Rick Merrill, Nov 19, 2009
    #2
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  3. andy

    Jordon Guest

    andy wrote:
    > Could someone throw some light on this one - it's doing my head in ...
    > Laptop running vista home premium and ext hd worked until recently
    > but now can't be seen by computer when connected to any usb port
    > - no drive letter shows in * computer * but drive shows in device
    > manager as working properly .


    I'm not familiar with Vista so YMMV...

    Right-click My Computer, select Disk Management. Can you
    see it there? If so, right-click it and change the drive
    letter.

    --
    Jordon
     
    Jordon, Nov 19, 2009
    #3
  4. andy

    andy Guest

    On Thu, 19 Nov 2009 13:10:38 -0800, Evan Platt
    <> wrote:

    >On Thu, 19 Nov 2009 21:07:29 GMT, andy <> wrote:
    >
    >>Could someone throw some light on this one - it's doing my head in ...
    >>Laptop running vista home premium and ext hd worked until recently
    >>but now can't be seen by computer when connected to any usb port
    >>- no drive letter shows in * computer * but drive shows in device
    >>manager as working properly . There is also usb icon shown in task bar
    >>I bought a new portable usb HD drive today and have the same problem
    >>with that.
    >>Strange thing is both work on other pc which is running windoze xp
    >>with no problem ......... also have no problem with usb memory sticks
    >>on both computers . Why is it just the portable drives ?
    >>Any help most appreciated Cheers

    >
    >See if you can "change" the drive mapping for that drive on the
    >computer?
    >
    >http://pcsupport.about.com/od/windowsvista/ht/chdrlettervista.htm
    >
    >Evan


    Now sorted - my son just had a look at things and somehow managed to
    assign a letter to drive in disc management - did it in safe mode .
    Pity he didn't help before ........ guess he wanted to see how far his
    old dad could go on his own ;-)

    Thanks for help
     
    andy, Nov 19, 2009
    #4
  5. andy

    softnfurry Guest

    "andy" <> wrote in message
    news:...
    > Could someone throw some light on this one - it's doing my head in ...
    > Laptop running vista home premium and ext hd worked until recently
    > but now can't be seen by computer when connected to any usb port
    > - no drive letter shows in * computer * but drive shows in device
    > manager as working properly . There is also usb icon shown in task bar
    > I bought a new portable usb HD drive today and have the same problem
    > with that.
    > Strange thing is both work on other pc which is running windoze xp
    > with no problem ......... also have no problem with usb memory sticks
    > on both computers . Why is it just the portable drives ?
    > Any help most appreciated Cheers


    It's not the Drives, It's the USB Drivers....
    If you are on Vista SP1 there was a USB problem with Hotfix KB936824 and
    KB940199 a while ago.

    You can disable the enhance pci to usb host controller in the device
    manager, this will make your devices reappear but apparently only wok at
    usb1.1 speeds.

    Or, to restore correct drivers AND USB 2.0 speeds (Works on 90% of PC's I
    have had with same problem).....
    Look in C:\Windows\System32\DriverStore\FileRepository and see if there are
    two or more folders named "usbstor.inf" with different sets of numbers
    attached to the end of the folder name... Then look in C:\Windows\inf folder
    and see if the usbstor.inf and usb stor.pnf files are missing, or check in
    the C:\Windows\System32\DriverStore\FileRepository for a NEWER VERSION. If
    so, copy the NEWEST pnf and inf files from the most recently updated
    usbstor.inf folder to C:\Windows\inf. Open the update driver wizard and
    reinstall your USB drivers. This will cure it (If that's the problem). If
    you have iPods etc on USB not working, do the same for usbaapl.sys Etc
    Etc...
    If any file tells you Permission denied, right-click the files and select
    properties, then click on security, advanced , Permissions and click edit.
    Then you add your name where it says "enter the object or name to select".
    Click ok the click on security and edit. Highlight your name in the "group
    or username box" and click "allow full control" in the permissions for
    everyone box then apply and ok then ok again. now that you have full control
    of the file you will be able to copy it to the required folder to get all
    your usb devices working .

    If that doesn't work, you can try (last effort before format & reinstall) to
    locate and delete the file INFCACHE.1, which may be corrupted and causing
    the problem. To delete this file, you will first have to modify its
    permissions so the users group can access it (right-click on the
    file->Properties->Security). INFCACHE.1 file. It's located at
    C:\Windows\inf (scroll down to the file). (Note: to see INFCACHE.1, you must
    set Windows Explorer to display hidden and system files).
     
    softnfurry, Nov 19, 2009
    #5
  6. andy

    Aardvark Guest

    On Thu, 19 Nov 2009 15:44:09 -0800, Evan Platt wrote:

    > On Thu, 19 Nov 2009 23:03:45 GMT, andy <> wrote:
    >
    >>Now sorted - my son just had a look at things and somehow managed to
    >>assign a letter to drive in disc management - did it in safe mode .
    >>Pity he didn't help before ........ guess he wanted to see how far his
    >>old dad could go on his own ;-)
    >>
    >>Thanks for help

    >
    > Glad you got it working.. This now means chucktard will be along in a
    > few hours to suggest what everyone else has already suggested and you've
    > confirmed as working.
    >
    > But of course, he'll see this (even though he supposedly killfiled me)
    > and won't post it now of course.


    You think he'll be able to help himself?



    --
    Well, of course, this is just the sort of blinkered philistine pig-
    ignorance I've come to expect from you non-creative garbage! You sit
    there on your loathsome spotty behinds squeezing blackheads, never
    caring a tinker's cuss for the struggling artist. You excrement!
     
    Aardvark, Nov 20, 2009
    #6
  7. andy

    VanguardLH Guest

    Rick Merrill wrote:

    > andy wrote:
    >> Could someone throw some light on this one - it's doing my head in ...
    >> Laptop running vista home premium and ext hd worked until recently
    >> but now can't be seen by computer when connected to any usb port
    >> - no drive letter shows in * computer * but drive shows in device
    >> manager as working properly . There is also usb icon shown in task bar
    >> I bought a new portable usb HD drive today and have the same problem
    >> with that.
    >> Strange thing is both work on other pc which is running windoze xp
    >> with no problem ......... also have no problem with usb memory sticks
    >> on both computers . Why is it just the portable drives ?
    >> Any help most appreciated Cheers

    >
    > You should have only one (1) "primary" partition on any drive, AFIK.


    Not true. You can have up to 4 partitions on a mass storage device (aka
    hard disk) under the standard BIOS routine. Those partitions can be
    primary or extended (with logical drives). So the partition setups that
    you could have:

    - N primary partitions.
    - 4-N extended partitions.

    where N ranges from 0 to 4. I don't remember the max for the number of
    logical drives within an extended partition. I could Google for it but
    my point was to rebuke your claim of 1 primary partition maximum. I did
    find http://en.wikipedia.org/wiki/Extended_boot_record but it doesn't
    state there is a max number of extended boot records.

    Unlike primary or extended partitions that are defined in one of the
    four partition records in the partition table in the MBR in the first
    sector (normally in the first sector of the first disk found by the
    BIOS), logical drives are defined within the extended partition. With
    Windows having a maximum of 26 drive letters with the first 2 reserved
    for floppy devices, there wouldn't be a point of defining more than 24-M
    logical drives where M is the number of drives you defined in primary
    partitions (and that's a total across all hard disks). *nix isn't
    similarly limited as it doesn't use drive letters (a *nix guru could
    better answer this part).

    What you might've meant is that only one partition record (to defined a
    partition) can be tagged as "active" in the partition table in the MBR
    on a hard disk.

    I have had anywhere from 1 to 4 primary partitions on a hard disk at a
    time. This is the easy setup for multi-boot scenarios where you install
    a different OS (a separate instance where each could be the same or
    different version of an OS) in each primary partition. You then use a
    boot manager that usurps the bootstrap code in the MBR that lets you
    select which primary partition is active, and the BIOS will load the OS
    loader in the boot (first) sector on that active partition. I could
    have Windows XP in 2 primary partitions (one for production and one for
    test), Solaris in a 3rd primary partition, and Redhat or some Linux in
    the 4th. If I use a multiboot manager that will work with logical
    drives in partitions, I can have even more OS'es setup to select from
    which to boot. And several multi-boot managers will even let you select
    a primary partition or logical drive in an extended partition on a disk
    other than the first one discovered by the BIOS. Some will even change
    the partition type in the partition table to mark it hidden so the OS
    shouldn't (notice I say shouldn't) see it to keep that OS isolated from
    another OS; however, although Windows 2000+ can see those partitions, it
    won't assign a drive letter and provides some protection against
    accidental or malicious corruption of files in the hidden partition.

    http://www.pcguide.com/ref/hdd/file/structPartitions-c.html
    http://www.ntfs.com/logdrives.htm
    http://en.wikipedia.org/wiki/Disk_partitioning
     
    VanguardLH, Nov 20, 2009
    #7
  8. andy

    VanguardLH Guest

    andy wrote:

    > Could someone throw some light on this one - it's doing my head in ...
    > Laptop running vista home premium and ext hd worked until recently
    > but now can't be seen by computer when connected to any usb port
    > - no drive letter shows in * computer * but drive shows in device
    > manager as working properly . There is also usb icon shown in task bar
    > I bought a new portable usb HD drive today and have the same problem
    > with that.
    > Strange thing is both work on other pc which is running windoze xp
    > with no problem ......... also have no problem with usb memory sticks
    > on both computers . Why is it just the portable drives ?
    > Any help most appreciated Cheers


    No drive *letter* shows in Windows Explorer.
    The *disk* shows up in Disk Management.

    Drive letters are assigned to partitions in a hard disk. That a
    partition on a disk does not show up in Windows Explorer means a drive
    *letter* was not assigned to it (i.e., it is a hidden partition). Just
    because a drive letter has not been assigned doesn't mean Disk Mgmt
    can't see the *device* and the partitions on it.

    Does Disk Management show a drive *letter* is assigned to that partition
    on the hard disk (when it is obviously plugged into a USB port)? If
    not, can you assign a drive letter to that partition on that disk
    (right-click on the partition)?

    With the USB disk plugged in and seen listed in Disk Management, see if
    using its scan function (Action -> Rescan disks) to re-register or make
    unique the disk signatures in the MBR (master boot record) of each
    device will help with recognition.

    Do other USB devices, like a flash thumb drive, work in those same USB
    ports?

    Does the external drive manufacturer provide a diagnostic utility that
    you can run against the device? Since Disk Management can see the
    device, a diagnostic utility should be able to communicate to it
    (provided it supports USB-connected devices). How do you know your
    external drive isn't toast? The USB-to-(P|S)ATA interface on the logic
    board inside its case might be functioning but not the drive itself.
    The device's logic can be detected but the drive may not be functional.
    Flash drives can withstand more severe shock than do rotating platters
    and floating heads in hard disks. Perhaps your external device took a
    shock while its platters were still spinning. External drives require
    some care in their handling.
     
    VanguardLH, Nov 20, 2009
    #8
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